Vehicle system

ABSTRACT

A vehicle system includes: a map processing unit that creates local map data based on high accuracy map data and a position of an own vehicle; an autonomous driving control unit that creates a travel plan based on the local map data and controls traveling of the own vehicle according to the travel plan; and a map guidance unit that, based on a set destination, sets a route to the destination. The map processing unit creates multiple pieces of transmission data by dividing the local map data so as to correspond to regions on a map, selects pieces of transmission data corresponding to regions located within a prescribed distance from the own vehicle and including the route to the destination as first transmission data, and transmits the first transmission data to the autonomous driving control unit with a higher priority than other pieces of transmission data.

TECHNICAL FIELD

The present invention relates to a vehicle system.

BACKGROUND ART

JP2019-184499A discloses a vehicle system including a map processingunit that creates map information necessary for autonomous driving byprocessing high accuracy map information and an autonomous drivingcontrol unit that performs autonomous driving control based on the mapinformation created by the map processing unit. Since the transmissiondata transmitted from the map processing unit to the autonomous drivingcontrol unit based on the map information has a large data amount, thevehicle system of JP2019-184499A restricts the map regions included inthe transmission data to suppress the data amount.

In the autonomous driving of the vehicle, the map processing unitsuccessively creates pieces of transmission data in accordance with theposition of the vehicle and transmits the pieces of transmission data tothe autonomous driving control unit. The autonomous driving control unitperforms autonomous driving control based on the map information, andtherefore, before the vehicle reaches a prescribed region, theautonomous driving control unit needs to have received the piece oftransmission data corresponding to the region. Accordingly, the mapprocessing unit is required to select regions in which the vehicle willbe likely to travel and to output the corresponding map information tothe autonomous driving control unit.

SUMMARY OF THE INVENTION

In view of the foregoing background, a primary object of the presentinvention is to provide a vehicle system which can select regions inwhich the vehicle will be likely to travel and output the correspondingmap information to the autonomous driving control unit.

To achieve the above object, one aspect of the present inventionprovides a vehicle system (1) comprising: a map processing unit (33)that creates local map data based on high accuracy map data and aposition of an own vehicle by extracting data of regions near the ownvehicle from the high accuracy map data; an autonomous driving controlunit (32) that receives the local map data from the map processing unit,creates a travel plan for autonomous traveling of the own vehicle basedon the local map data, and controls traveling of the own vehicleaccording to the travel plan; and a map guidance unit (11) that, basedon a set destination, sets a route to the destination, wherein the mapprocessing unit creates multiple pieces of transmission data by dividingthe created local map data so as to correspond to regions on a map,selects, from the multiple pieces of transmission data, pieces oftransmission data corresponding to regions having a distance from theown vehicle less than or equal to a prescribed distance and includingthe route to the destination as first transmission data, and transmitsthe first transmission data to the autonomous driving control unit witha higher priority than other pieces of transmission data.

According to this aspect, in the vehicle system, it is possible toselect regions in which the vehicle will be likely to travel and tooutput the corresponding map information to the autonomous drivingcontrol unit. Since the map processing unit creates and transmits thetransmission data for the regions including the route to the destinationpreferentially over the transmission data for the other regions, theautonomous driving control unit can preferentially acquire the mapinformation necessary for autonomous driving.

In the above aspect, preferably, the map processing unit transmits thepieces of transmission data selected as the first transmission data tothe autonomous driving control unit sequentially starting from a pieceof transmission data corresponding to a region nearest to the ownvehicle.

According to this aspect, the autonomous driving control unit canacquire the pieces of map data necessary for autonomous driving in theorder they become necessary.

In the above aspect, preferably, the map processing unit selects, fromthe multiple pieces of transmission data, pieces of transmission datacorresponding to regions having a distance from the own vehicle lessthan or equal to the prescribed distance and including a branch routethat branches off from the route to the destination as secondtransmission data, and transmits the second transmission data to theautonomous driving control unit with a higher priority than othertransmission data excluding the first transmission data.

According to this aspect, the map processing unit creates thetransmission data for the regions including the branch route andtransmits the transmission data to the autonomous driving control unitpreferentially next to the transmission data for the regions includingthe route to the destination. Thereby, the autonomous driving controlunit can continue autonomous driving even when the route to thedestination is changed.

In the above aspect, preferably, the map processing unit transmits thepieces of transmission data selected as the second transmission data tothe autonomous driving control unit sequentially starting from a pieceof transmission data corresponding to a region nearest to a branch pointof the branch route from the route to the destination.

According to this aspect, the autonomous driving control unit cancontinue autonomous driving even when the route to the destination ischanged.

In the above aspect, preferably, the map processing unit selects, fromthe multiple pieces of transmission data, pieces of transmission datacorresponding to regions having a distance from the own vehicle lessthan or equal to the prescribed distance and including a merging routethat merges with the route to the destination as third transmissiondata, and transmits the third transmission data to the autonomousdriving control unit with a higher priority than other transmission dataexcluding the first transmission data and the second transmission data.

According to this aspect, the autonomous driving control unit canrecognize a route that merges with the route to the destination and canrecognize the behavior of the vehicles traveling on the merging route.

In the above aspect, preferably, the map processing unit transmits thepieces of transmission data selected as the third transmission data tothe autonomous driving control unit sequentially starting from a pieceof transmission data corresponding to a region nearest to a merge pointof the merging route with the route to the destination.

According to this aspect, the autonomous driving control unit canacquire the map information for the merging route sequentially startingfrom the map data for the region nearest to the merge point.

According to the foregoing configuration, it is possible, in the vehiclesystem, to select regions in which the vehicle will be likely to traveland to output the corresponding map information to the autonomousdriving control unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration diagram of a vehicle system according to anembodiment of the present invention;

FIG. 2 is a flowchart showing a procedure of a map providing processexecuted by a map providing unit;

FIG. 3 is a flowchart showing a procedure of a transmission orderdecision process executed by the map providing unit;

FIG. 4 is an explanatory diagram showing an example of a transmissionorder of pieces of transmission data;

FIG. 5A is an explanatory diagram showing regions corresponding topieces of transmission data in a case where the congestion degree ishigh;

FIG. 5B is an explanatory diagram showing regions corresponding topieces of transmission data in a case where the congestion degree islow; and

FIG. 6 is an explanatory diagram showing a case where pieces oftransmission data are created for respective lanes.

DETAILED DESCRIPTION OF THE INVENTION

In the following, a vehicle system according to an embodiment of thepresent invention will be described with reference to the drawings.

(Vehicle System)

As shown in FIG. 1, a vehicle system 1 is connected with a map server 3via a network. The vehicle system 1 includes a powertrain 4, a brakedevice 5, a steering device 6, an external environment sensor 7, avehicle sensor 8, a communication device 9, a GNSS receiver 10, anavigation device 11 (map guidance unit), an operation input member 12,a driving operation sensor 13, a human machine interface (HMI) 14, and acontrol device 16. These components of the vehicle system 1 areconnected to each other so that signals can be transmitted therebetweenvia communication means such as a Controller Area Network (CAN).

The powertrain 4 is a device configured to apply a driving force to thevehicle. The powertrain 4 includes at least one of an internalcombustion engine, such as a gasoline engine and a diesel engine, and anelectric motor. The brake device 5 is a device configured to apply abrake force to the vehicle. For example, the brake device 5 includes abrake caliper configured to press a brake pad against a brake rotor andan electric cylinder configured to supply an oil pressure to the brakecaliper. The brake device 5 may include a parking brake deviceconfigured to restrict rotations of wheels via a wire cable. Thesteering device 6 is a device for changing the steering angle of thewheels. For example, the steering device 6 includes a rack-and-pinionmechanism configured to steer the wheels and an electric motorconfigured to drive the rack-and-pinion mechanism. The powertrain 4, thebrake device 5, and the steering device 6 are controlled by the controldevice 16.

The external environment sensor 7 is a sensor that detectselectromagnetic waves, sound waves, and the like from the surroundingsof the vehicle to detect an object outside the vehicle. The externalenvironment sensor 7 includes sonars 17 and external cameras 18. Theexternal environment sensor 7 may include a millimeter wave radar and/ora laser lidar. The external environment sensor 7 outputs a detectionresult to the control device 16.

Each sonar 17 consists of a so-called ultrasonic sensor. The sonar 17emits ultrasonic waves to the surroundings of the vehicle and capturesthe ultrasonic waves reflected by an object around the vehicle therebyto detect a position (distance and direction) of the object. Multiplesonars 17 are provided at each of a rear part and a front part of thevehicle.

The external cameras 18 are devices configured to capture images aroundthe vehicle. Each external camera 18 consists of a digital camera usinga solid imaging element, such as a CCD or a CMOS, for example. Eachexternal camera 18 may be a stereo camera or a monocular camera. Theexternal cameras 18 may include a front camera for capturing an image infront of the vehicle, a rear camera for capturing an image to the rearof the vehicle, and a pair of side cameras for capturing images on leftand right side of the vehicle.

The vehicle sensor 8 is a sensor that measures a state of the vehicle.The vehicle sensor 8 includes a vehicle speed sensor configured todetect the speed of the vehicle, an acceleration sensor configured todetect acceleration of the vehicle, a yaw rate sensor configured todetect the angular velocity around a vertical axis of the vehicle, and adirection sensor configured to detect the direction of the vehicle. Forexample, the yaw rate sensor consists of a gyro sensor. The vehiclesensor 8 may include a tilt sensor configured to detect the tilt of thevehicle body and a wheel speed sensor configured to detect the rotationspeed of one or more wheels.

The communication device 9 mediates communication between the controldevice 16 and devices outside the vehicle (for example, the map server3). The communication device 9 includes a router for connecting thecontrol device 16 to the Internet. The communication device 9 preferablyhas a wireless communication function that mediates wirelesscommunication between the control device 16 and a control device 16 ofanother vehicle around the own vehicle and/or wireless communicationbetween the control device 16 and roadside devices on the road.

The GNSS receiver 10 receives a signal (hereinafter referred to as a“GNSS signal”) from multiple satellites constituting a global navigationsatellite system (GNSS). The GNSS receiver 10 outputs the received GNSSsignal to the navigation device 11 and the control device 16.

The navigation device 11 is configured by a computer made of knownhardware. The navigation device 11 identifies the current position(latitude and longitude) of the vehicle based on the latest travelhistory and/or the GNSS signal output from the GNSS receiver 10. Thenavigation device 11 is provided with a RAM, a HDD, an SSD or the likefor storing data related to the road information in the areas and/orcountries in which the vehicle may travel (hereinafter referred to as“navigation map data”).

The navigation device 11 sets a route from the current position of thevehicle to the destination input by an occupant of the vehicle based onthe GNSS signal and the navigation map data and outputs the route to thecontrol device 16. When the vehicle starts traveling, the navigationdevice 11 provides the occupant with a route guide to the destination.

The navigation device 11 holds, as the information related to the roadson the map, information regarding points (nodes) on the roads and linesegments (links) connecting the nodes. Preferably, the nodes held in thenavigation device 11 are provided at feature points such asintersections and merge points, for example. The navigation device 11stores the distance between the nodes connected by each link inassociation with the information of each link. The navigation device 11acquires an appropriate route from the current position of the vehicleto the destination based on the distances between the nodes and outputsinformation indicating the route to the control device 16. The outputinformation indicating the route includes the points (nodes) on theroads corresponding to the route and the links corresponding to thevectors connecting the nodes.

The operation input member 12 is provided in a vehicle cabin to receivean input operation performed by the occupant to control the vehicle. Theoperation input member 12 includes a steering wheel, an acceleratorpedal, and a brake pedal. The operation input member 12 may furtherinclude a shift lever, a parking brake lever, a turn signal lever, orthe like.

The driving operation sensor 13 is a sensor that detects an operationamount of the operation input member 12. The driving operation sensor 13includes a steering angle sensor configured to detect an operationamount of the steering wheel, an accelerator sensor configured to detectan operation amount of the accelerator pedal, and a brake sensorconfigured to detect an operation amount of the brake pedal. The drivingoperation sensor 13 outputs a detected operation amount to the controldevice 16. The driving operation sensor 13 may include a grasp sensorconfigured to detect grasping of the steering wheel by the occupant. Forexample, the grasp sensor is constituted of an electrostatic capacitancesensor provided on an outer circumferential portion of the steeringwheel.

The HMI 14 notifies the occupant of various kinds of information bydisplay and/or voice and receives an input operation by the occupant.The HMI 14 includes, for example, a touch panel 23 that includes aliquid crystal display or an organic EL display and is configured toreceive the input operation by the occupant and a sound generationdevice 24 such as a buzzer or a speaker. The HMI 14 is capable ofdisplaying a driving mode switching button on the touch panel 23. Thedriving mode switching button is a button for receiving an operation ofthe occupant to switch the driving mode (for example, an autonomousdriving mode and a manual driving mode) of the vehicle.

The HMI 14 also functions as an interface that mediates output and inputto and from the navigation device 11. Namely, when the HMI 14 receives adestination input operation by the occupant, the navigation device 11starts setting a route to the destination. Also, when the navigationdevice 11 performs the route guidance to the destination, the HMI 14displays the current position of the vehicle and the route to thedestination.

The control device 16 is configured by one or more electronic controlunits (ECUs) each including a CPU, a ROM, a RAM, and the like. The CPUexecutes operation processing according to a program so that the controldevice 16 executes various types of vehicle control. The control device16 may consist of one piece of hardware or may consist of a unitincluding multiple pieces of hardware. Further, the functions of thecontrol device 16 may be at least partially executed by hardware such asan LSI, an ASIC, and an FPGA or may be executed by a combination ofsoftware and hardware.

(Control Device 16)

As shown in FIG. 1, the control device 16 includes an externalenvironment recognizing unit 31, an autonomous driving control unit 32(Advanced Driver-Assistance System, ADAS), and a map positioning unit(MPU) 33 serving as a map processing unit. These components may beconfigured by separate electronic control units connected with oneanother via a gateway (central gateway (CGW)). Alternatively, thecomponents may be configured by an integral electronic control unit.

The external environment recognizing unit 31 recognizes target objectspresent around the vehicle based on the detection result of the externalenvironment sensor 7, and thereby obtains information related to theposition and size of each target object. The target objects recognizedby the external environment recognizing unit 31 include delimiting linesdrawn on the travel road of the vehicle, lanes, roadsides, shoulders,obstacles, etc.

The delimiting lines are lines drawn along the vehicle travel direction.The lanes are regions delimited by one or more delimiting lines. Theroadsides are end portions of the travel road of the vehicle. A shoulderis a region between one roadside and the delimiting line adjacent to theroadside in the vehicle width direction. Obstacles include, for example,protective walls (guardrails), utility poles, surrounding vehicles,pedestrians, and so on.

The external environment recognizing unit 31 analyzes the imagescaptured by the external cameras 18 thereby to recognize the positionsof the target objects present around the vehicle relative to thevehicle. For example, the external environment recognizing unit 31 mayrecognize the distance and direction from the vehicle to each targetobject as viewed from directly above with respect to the vehicle body,by means of a known method such as triangulation method or a motionstereo method. Further, the external environment recognizing unit 31analyzes the images captured by the external cameras 18 and determinethe kind of each target object (for example, a delimiting line, a lane,a roadside, a shoulder, an obstacle, etc.) based on a known method.

The map positioning unit 33 includes a map acquisition unit 51, a mapstorage unit 52, an own vehicle position identifying unit 53, a maplinkage unit 54, an additional information storage unit 55, arecommended lane setting unit 56, a localization functional unit 57, anda map providing unit 58.

The map acquisition unit 51 accesses the map server 3 and acquiresdynamic map data, which is high accuracy map information, from the mapserver 3. For example, when the navigation device 11 has set a route,the map acquisition unit 51 preferably acquires the latest dynamic mapdata of the area corresponding to the route from the map server 3 viathe communication device 9.

The dynamic map data is more detailed map data than the map data held inthe navigation device 11 and includes static information, semi-staticinformation, semi-dynamic information, and dynamic information. Thestatic information includes three-dimensional map data having higheraccuracy than the navigation map data. The semi-static informationincludes traffic restriction information, road construction information,and wide area weather information. The semi-dynamic information includesaccident information, traffic jam information, and narrow area weatherinformation. The dynamic information includes, traffic lightinformation, surrounding vehicle information, and pedestrianinformation.

The static information (high accuracy map) of the dynamic map dataincludes information related to the lanes on the travel road (forexample, the number of lanes) and information related to the delimitinglines on the travel road (for example, types of the delimiting lines).For example, each delimiting line of the static information isrepresented by nodes disposed at distances smaller than those betweenthe nodes of the navigation map data and link connecting the nodes.

Besides, each roadway of the static information also is represented bynodes disposed at a prescribed interval (hereinafter, roadway nodes) andlinks connecting the nodes (hereinafter, roadway links). Each roadwaynode is created in the middle between a node of the delimiting line setat the left side end of the road and a node of the delimiting line setat the right side end of the road. The nodes of each roadway link areprovided at a prescribed interval along the road.

The map storage unit 52 includes one or more storage devices such as anHDD and an SSD and holds various information necessary for autonomoustravel of the vehicle in the autonomous driving mode. The map storageunit 52 stores the dynamic map data that the map acquisition unit 51 hasacquired from the map server 3.

The own vehicle position identifying unit 53 identifies the position ofthe vehicle (latitude and longitude) based on the GNSS signal outputfrom the GNSS receiver 10.

Also, the own vehicle position identifying unit 53 uses the detectionresult of the vehicle sensor 8 (an inertial measurement unit (IMU) orthe like) to calculate the movement amount of the vehicle (movementdistance and movement direction of the vehicle) by dead reckoning (forexample, odometry). The movement amount of the vehicle calculated bydead reckoning will be referred to as a DR movement amount hereinafter.The own vehicle position identifying unit 53 identifies the own vehicleposition based on the DR movement amount when the GNSS signal cannot bereceived, for example. Also, the own vehicle position identifying unit53 may execute a process of correcting the own vehicle positionidentified from the GNSS signal based on the DR movement amount therebyto improve the identification accuracy of the own vehicle position.

The map linkage unit 54 extracts, based on the route output from thenavigation device 11, a corresponding route from the high accuracy mapheld by the map storage unit 52 and outputs the extracted route to thelocalization functional unit 57.

The additional information storage unit 55 stores pieces of roadadditional information associated with the links of the dynamic map.Each link of the dynamic map is given an identification number, and thepiece of road additional information related to a certain link isidentified by the identification number of the link. Each piece of roadadditional information preferably includes unique information notincluded in the dynamic map. For example, a piece of road additionalinformation may include information indicating that the related lane isa region in which the reception level of the GNSS signal is lower than aprescribed level. More specifically, a piece of road additionalinformation may preferably indicate that the related link is positionedunder an elevated road, the related link is positioned in a tunnel, orthe related link is surrounded by high-rise buildings.

The recommended lane setting unit 56 selects, from among the lane linksoutput by the map linkage unit 54, recommended lane links suitable forthe travel of the vehicle based on the route, the information held bythe dynamic map, etc. For example, when the route extracted by the maplinkage unit 54 includes a branch road, the recommended lane settingunit 56 adds, to the recommended lane information of the lane linkcorresponding to the lane suitable for entrance to the branch road (forexample, the lane link of the lane that is 2 km before the entrance tothe branch road and is nearest to the branch road), data indicating thatthe lane is suitable for the travel of the vehicle, and makes the mapstorage unit 52 store the data.

The localization functional unit 57 acquires a high accuracy map of arelatively narrow region around the vehicle and in the direction oftravel of the vehicle based on the own vehicle position identified bythe own vehicle position identifying unit 53 and the route extracted bythe map linkage unit 54. Thereafter, the localization functional unit 57identifies the travel lane and the own vehicle position in the travellane from the positions of the delimiting lines identified by theexternal environment recognizing unit 31 and the like by using theacquired high accuracy map and the own vehicle position identified bythe own vehicle position identifying unit 53. In addition, thelocalization functional unit 57 creates a local map at all times byadding information on the vehicle surroundings identified by theexternal environment recognizing unit 31 (for example, information onobstacles) to the acquired high accuracy map.

The localization functional unit 57 may add the road additionalinformation stored in the additional information storage unit 55 to thelocal map. In this case, the localization functional unit 57 identifiesthe links whose road additional information is to be added based on theidentification numbers. Thereby, the links included in the local map areassociated with the corresponding road additional information.

The map providing unit 58 divides the local map data so as to correspondto the regions on the map thereby to create multiple pieces oftransmission data, and transmits the multiple pieces of transmissiondata to the autonomous driving control unit 32 in order.

The autonomous driving control unit 32 includes an action plan unit 41,a travel control unit 42, and a mode setting unit 43.

The action plan unit 41 creates an action plan that defines futureaction of the vehicle based on the transmission data including the mapinformation received from the map positioning unit 33 and the externalenvironment information received from the external environmentrecognizing unit 31. The action plan may include events such asfollow-up traveling to follow the preceding vehicle, lane change,overtaking, turning to a branch road, etc. In each event, a targettrajectory of the vehicle is set. The action plan unit 41 outputs atravel control signal corresponding to the created action plan to thetravel control unit 42.

The travel control unit 42 controls the powertrain 4, the brake device5, and the steering device 6 based on the travel control signal from theaction plan unit 41. Namely, the travel control unit 42 makes thevehicle travel following the action plan created by the action plan unit41.

In the following, description will be made of a method with which themap providing unit 58 creates transmission data from the local map andtransmits the transmission data to the autonomous driving control unit32. The map providing unit 58 executes a map providing process shown inFIG. 2. In the map providing process, the map providing unit 58 firstacquires the road traffic information at the own vehicle position basedon the own vehicle position and the dynamic map (S1). The dynamic mapincludes the road traffic information as the dynamic information. Theroad traffic information includes traffic jam information, constructioninformation, and lane restriction information. In the presentembodiment, the map providing unit 58 acquires the traffic jaminformation in the region corresponding to the own vehicle position. Themap providing unit 58 may acquire the road traffic information includingthe traffic jam information from the local map instead of the dynamicmap. Since the local map is created based on the dynamic map, the localmap can include the road traffic information included in the dynamicinformation of the dynamic map.

Subsequently, the map providing unit 58 sets an upper limit value of anarea of the region on the map corresponding to each piece oftransmission data based on the road traffic information (S2). Forexample, the map providing unit 58 acquires the congestion degree of theroad on which the own vehicle is traveling based on the road trafficinformation, and the higher the congestion degree is, the smaller themap providing unit 58 sets the upper limit value of the area of theregion on the map corresponding to each piece of transmission data.

Then, the map providing unit 58 divides the local map data so as tocorrespond to the regions on the map thereby to create multiple piecesof transmission data (S3). Each piece of transmission data includesmultiple nodes and at least one link. The region corresponding to eachpiece of transmission data includes multiple nodes disposed in theextension direction of the lane and at least one link connecting themultiple nodes. Also, each piece of transmission data may includemultiple nodes and multiple links corresponding to multiple lanes thatare disposed in parallel. Adjacent regions corresponding to respectivepieces of transmission data are connected with each other at thenode(s). Multiple nodes are disposed on a boundary of the regioncorresponding to each piece of transmission data.

The shape of the region corresponding to each piece of transmission datapreferably is quadrilateral, such as rectangle or square. In anotherembodiment, the shape of the region corresponding to each piece oftransmission data may be any polygon such as triangle or pentagondepending on the shape formed by the multiple nodes and links.

Preferably, the map providing unit 58 creates each piece of transmissiondata such that the attributes set for the respective links included ineach piece of transmission data are identical. The map providing unit 58sets the pieces of transmission data such that the area of the region onthe map corresponding to each piece of transmission data is smaller thanor equal to the upper limit value set in step S2. Namely, the mapproviding unit 58 changes the area of the region on the mapcorresponding to each piece of transmission data based on the roadtraffic information. Also, the map providing unit 58 preferably createsthe pieces of transmission data by dividing the region positioned withina prescribed distance from the position of the own vehicle. By includingthe links having the same attribute in a single piece of transmissiondata, it is possible to compress the data amount.

Also, the map providing unit 58 preferably creates each piece oftransmission data such that the road additional information associatedwith each link is identical. Namely, it is preferable that the linkshaving different road additional information are included in differentpieces of transmission data. By including links having the identicalroad additional information in a single piece of transmission data, itis possible to compress the data amount.

Then, the map providing unit 58 executes a transmission order decisionprocess to decide the order of transmission of the created multiplepieces of transmission data to the autonomous driving control unit 32(S4). The transmission order decision process is executed according tothe procedure shown by the flowchart of FIG. 3.

In the transmission order decision process, the map providing unit 58first extracts the pieces of transmission data corresponding to theregions positioned within a prescribed distance from the own vehicle(S11). FIG. 4 is an explanatory diagram showing pieces of transmissiondata set based on the route and priority orders of the pieces oftransmission data. In FIG. 4, the route includes a route R1 to thedestination, a branch route R2 that branches off from the route R1 tothe destination, and a merging route R3 that merges with the route R1 tothe destination. The route R1 to the destination, the branch route R2,and the merging route R3 have multiple nodes N representing points onthe lanes and links L each connecting two nodes N adjacent to each otherin an extension direction of a lane. The direction of an arrow of eachlink L represents the direction of travel of the vehicle. The vehiclecan enter the branch route R2 from the route R1 to the destination, butthe vehicle cannot enter the merging route R3 from the route R1 to thedestination. For example, in a case where the route R1 to thedestination is a highway, the branch route includes an exit ramp of thehighway, and the merging route includes an entrance ramp of the highway.The position of the vehicle is represented by a white triangle. Theroute R1 to the destination includes three parallel lanes.

The transmission data for the route R1 to the destination is divided soas to correspond to blocks B1 to B5 on the map, the transmission datafor the branch route R2 is divided so as to correspond to blocks B6 toB9, and the transmission data for the merging route R3 is divided so asto correspond to blocks B10 to B13. With the process of step S11, themap providing unit 58 extracts the pieces of transmission datacorresponding to the blocks B1 to B13, namely, the pieces oftransmission data corresponding to the regions positioned within aprescribed distance from the own vehicle.

Subsequently, the map providing unit 58 extracts, from the multiplepieces of transmission data extracted in step S11, multiple pieces oftransmission data corresponding to the regions including the route tothe destination, and sets them as first transmission data (S12). In theexample of FIG. 4, the pieces of transmission data corresponding to theblocks B1 to B5 are set as the first transmission data. The multiplepieces of transmission data included in the first transmission data aregiven priority orders such that a piece of transmission datacorresponding to a region nearer to the position of the own vehicle isgiven a higher priority order. Thus, the priority orders are set for themultiple pieces of transmission data included in the first transmissiondata corresponding to the blocks B1 to B5 such that the priority ordersare high in the order of B1 to B5.

Then, the map providing unit 58 extracts, from the multiple pieces oftransmission data extracted in step S11, multiple pieces of transmissiondata corresponding to regions including the branch route, and sets themas second transmission data (S13). In the example of FIG. 4, the piecesof transmission data corresponding to the blocks B6 to B9 are set as thesecond transmission data. The multiple pieces of transmission dataincluded in the second transmission data are given priority orders suchthat a piece of transmission data corresponding to a region nearer tothe branch point from the route to the destination is given a higherpriority order. Thus, the priority orders are set for the multiplepieces of transmission data included in the second transmission datacorresponding to the blocks B6 to B9 such that the priority orders arehigh in the order of B6 to B9.

Further, the map providing unit 58 extracts, from the multiple pieces oftransmission data extracted in step S11, multiple pieces of transmissiondata corresponding to the regions including the merging route, and setsthem as third transmission data (S14). In the example of FIG. 4, thepieces of transmission data corresponding to the blocks B10 to B13 areset as the third transmission data. The multiple pieces of transmissiondata included in the third transmission data are given priority orderssuch that a piece of transmission data corresponding to a region nearerto the merge point with the route to the destination is given a higherpriority order. Thus, the priority orders are set for the multiplepieces of transmission data included in the third transmission datacorresponding to the blocks B10 to B13 such that the priority orders arehigh in the order of B10 to B13.

After executing the transmission order decision process, the mapproviding unit 58 starts measurement of time (S5). In anotherembodiment, the map providing unit 58 may start measurement of traveldistance instead of starting measurement of time.

Subsequently, the map providing unit 58 identifies a single piece oftransmission data having the highest priority order from the pieces oftransmission data (S6). The transmission order is determined based onthe priority orders which are high in the order of the firsttransmission data, the second transmission data, the third transmissiondata, and the other data. As described above, the multiple pieces oftransmission data included in the first transmission data are givenpriority orders such that a piece of transmission data corresponding toa region nearer to the position of the own vehicle is given a higherpriority order. The multiple pieces of transmission data included in thesecond transmission data are given priority orders such that a piece oftransmission data corresponding to a region nearer to the branch pointfrom the route to the destination is given a higher priority order. Themultiple pieces of transmission data included in the third transmissiondata are given priority orders such that a piece of transmission datacorresponding to a region nearer to the merge point with the route tothe destination is given a higher priority order. For the pieces oftransmission data classified in the other transmission data, it ispreferable if a piece of transmission data corresponding to a regionnearer to the position of the own vehicle is given a higher priorityorder. Thus, in the example of FIG. 4, the pieces of transmission dataare given priority orders such that the priority orders are high in theorder of block B1 to the block B13.

Then, the map providing unit 58 determines whether the piece oftransmission data with the highest priority order identified in step S6matches the transmission data already transmitted to the autonomousdriving control unit 32 (S7). If the entirety of the piece oftransmission data with the highest priority order identified in step S6is included in the transmission data already transmitted to theautonomous driving control unit 32, the map providing unit 58 determinesthat the piece of transmission data with the highest priority orderidentified in step S6 matches the transmission data already transmittedto the autonomous driving control unit 32. If at least part of the pieceof transmission data with the highest priority order identified in stepS6 is not included in the transmission data already transmitted to theautonomous driving control unit 32, the map providing unit 58 determinesthat the piece of transmission data with the highest priority orderidentified in step S6 does not match the transmission data alreadytransmitted to the autonomous driving control unit 32. Thereby,transmission of overlapping transmission data to the autonomous drivingcontrol unit 32 is prevented.

If the determination result in step S7 is No, the map providing unit 58transmits the piece of transmission data with the highest priority orderidentified in step S6 to the autonomous driving control unit 32 (S8).

Thereafter, the map providing unit 58 determines whether the elapsedtime which is started to be measured in step S5 has become equal to orgreater than a prescribed determination time (S9). If the elapsed timeis less than the determination time (the determination result of S9 isNo), the map providing unit 58 returns to step S6 and identifies thepiece of transmission data with the next highest priority order. Whenthe elapsed time is equal to or greater than the determination time (thedetermination result of S9 is Yes), the map providing unit 58 repeatsthe process from step S1. Thereby, the map providing unit 58 cantransmit appropriate transmission data to the autonomous driving controlunit 32 according to the travel of the vehicle.

With the map providing process, the map providing unit 58 transmits thefirst transmission data to the autonomous driving control unit 32preferentially over the other transmission data. Also, the map providingunit 58 transmits the second transmission data to the autonomous drivingcontrol unit 32 preferentially over the other transmission dataexcluding the first transmission data. Further, the map providing unit58 transmits the third transmission data to the autonomous drivingcontrol unit 32 preferentially over the other transmission dataexcluding the first transmission data and the second transmission data.

According to this aspect, in the vehicle system 1, it is possible toselect regions in which the vehicle will be likely to travel and tooutput the corresponding map information to the autonomous drivingcontrol unit 32. Since the map providing unit 58 creates thetransmission data for the regions including the route R1 to thedestination and transmits it to the autonomous driving control unit 32preferentially over the transmission data for the other regions, theautonomous driving control unit 32 can preferentially acquire the mapinformation necessary for autonomous driving. Also, since the mapproviding unit 58 creates the transmission data for the regionsincluding the branch route R2 and transmits it to the autonomous drivingcontrol unit 32 preferentially next to the transmission data for theregions including the route R1 to the destination, the autonomousdriving control unit 32 can continue autonomous driving even when theroute to the destination R1 is changed. Further, by recognizing themerging route R3, the autonomous driving control unit 32 can recognizeand infer the behavior of the vehicles traveling on the merging routeR3.

In step S3, the map providing unit 58 may create pieces of transmissiondata such that the data amount of each piece of transmission data iswithin a prescribed range. Namely, the map providing unit 58 may makethe data amount of each piece of transmission data uniform. According tothis aspect, since the data amount of each piece of transmission data ismade uniform, the map providing unit 58 and the autonomous drivingcontrol unit 32 can efficiently process the pieces of transmission data.

According to the map providing process executed by the above-describedmap providing unit, the data amount of each piece of transmission datais changed based on the degree of vehicle congestion or the degree oftraffic jam included in the road traffic information. For example, whenthe congestion degree is low, blocks B21, B22 (regions) on the map eachcorresponding to a single piece of transmission data are set to berelatively long in the lane extension direction (see FIG. 5A). On theother hand, when the congestion degree is high, blocks B31 to B36 on themap each corresponding to a single piece of transmission data are set tobe shorter in the lane extension direction than when the congestiondegree is low (see FIG. 5B). Thereby, when the degree of vehiclecongestion is high, the data amount of each piece of transmission datais set smaller than when the degree of vehicle congestion is low. If anarea of the block represented by a single piece of transmission databecomes large, compression of the data amount becomes possible. Also,since the number of pieces of transmission data to which it is necessaryto give priority orders in transmission decreases, the calculation loadis reduced. When an area of the block represented by a single piece oftransmission data becomes small, it becomes possible to finely set thepriority orders in transmission.

In step S3, the map providing unit 58 may create transmission datadivided for each lane. And, the map providing unit 58 may transmitpieces of transmission data corresponding to only some of the multipleparallel lanes to the autonomous driving control unit 32. FIG. 6 showsan example in which blocks B41 to B43 are set so as to correspond to therespective lanes. According to this, it is possible to reduce the dataamount of each piece of transmission data transmitted from the mapproviding unit 58 to the autonomous driving control unit 32.

Preferably, the map providing unit 58 creates transmission data dividedfor each lane and transmits a piece of transmission data correspondingto the recommended lane set by the recommended lane setting unit 56 tothe autonomous driving control unit 32. In this case, preferably, themap providing unit 58 transmits only the piece of transmission datacorresponding to the recommended lane R4 of the multiple parallel lanesto the autonomous driving control unit 32.

The map providing unit 58 may change the shape and size of the region onthe map corresponding to each piece of transmission data based onselection information that decides a travel mode of the vehicle. Forexample, the selection information may indicate a frequency ofovertaking in the autonomous driving control, which is preferablyselected from “frequent overtaking” and “infrequent overtaking.”Preferably, the selection information can be set by the user. Theselection information is preferably input from the touch panel 23 by anoperation of the user, for example. The input selection information ispreferably stored in the storage device of the control device 16.

In the case where the selection information is set to “frequentovertaking,” it is preferable if the map providing unit 58 does notdivide a region including the parallel lanes into multiple regionscorresponding to the respective lanes and creates transmission databased on the integral (undivided) region. On the other hand, in the casewhere the selection information is set to “infrequent overtaking,” it ispreferable if the map providing unit 58 divides the region into multipleregions corresponding to the respective parallel lanes and creates thetransmission data based on only the region corresponding to therecommended lane.

Preferably, the map providing unit 58 creates transmission data dividedfor each lane in step S3 of the map providing process and sets thepriority order of the region corresponding to the recommended lane to behigher than that of the first transmission data in the transmissionorder decision process of step S4. Thereby, the autonomous drivingcontrol unit 32 can acquire the map information of the regioncorresponding to the recommended lane.

Concrete embodiments of the present invention have been described in theforegoing, but the present invention is not limited to the aboveembodiments and may be modified or altered in various ways.

1. A vehicle system comprising: a map processing unit that creates localmap data based on high accuracy map data and a position of an ownvehicle by extracting data of regions near the own vehicle from the highaccuracy map data; an autonomous driving control unit that receives thelocal map data from the map processing unit, creates a travel plan forautonomous traveling of the own vehicle based on the local map data, andcontrols traveling of the own vehicle according to the travel plan; anda map guidance unit that, based on a set destination, sets a route tothe destination, wherein the map processing unit creates multiple piecesof transmission data by dividing the created local map data so as tocorrespond to regions on a map, selects, from the multiple pieces oftransmission data, pieces of transmission data corresponding to regionshaving a distance from the own vehicle less than or equal to aprescribed distance and including the route to the destination as firsttransmission data, and transmits the first transmission data to theautonomous driving control unit with a higher priority than other piecesof transmission data.
 2. The vehicle system according to claim 1,wherein the map processing unit transmits the pieces of transmissiondata selected as the first transmission data to the autonomous drivingcontrol unit sequentially starting from a piece of transmission datacorresponding to a region nearest to the own vehicle.
 3. The vehiclesystem according to claim 1, wherein the map processing unit selects,from the multiple pieces of transmission data, pieces of transmissiondata corresponding to regions having a distance from the own vehicleless than or equal to the prescribed distance and including a branchroute that branches off from the route to the destination as secondtransmission data, and transmits the second transmission data to theautonomous driving control unit with a higher priority than othertransmission data excluding the first transmission data.
 4. The vehiclesystem according to claim 3, wherein the map processing unit transmitsthe pieces of transmission data selected as the second transmission datato the autonomous driving control unit sequentially starting from apiece of transmission data corresponding to a region nearest to a branchpoint of the branch route from the route to the destination.
 5. Thevehicle system according to claim 3, wherein the map processing unitselects, from the multiple pieces of transmission data, pieces oftransmission data corresponding to regions having a distance from theown vehicle less than or equal to the prescribed distance and includinga merging route that merges with the route to the destination as thirdtransmission data, and transmits the third transmission data to theautonomous driving control unit with a higher priority than othertransmission data excluding the first transmission data and the secondtransmission data.
 6. The vehicle system according to claim 5, whereinthe map processing unit transmits the pieces of transmission dataselected as the third transmission data to the autonomous drivingcontrol unit sequentially starting from a piece of transmission datacorresponding to a region nearest to a merge point of the merging routewith the route to the destination.